Apparent absence of Giardia infections among children under 5-years of age with acute watery diarrhoea in Abakaliki, Nigeria

High Diversity of Giardia duodenalis Assemblages and Sub-Assemblages in Asymptomatic School Children in Ibadan, Nigeria

Giardia duodenalis is a significant contributor to the burden of diarrheal disease in sub-Saharan Africa. This study assesses the occurrence and molecular diversity of G. duodenalis and other intestinal parasites in apparently healthy children (n = 311) in Ibadan, Nigeria. Microscopy was used as a screening method and PCR and Sanger sequencing as confirmatory and genotyping methods, respectively. Haplotype analyses were performed to examine associations between genetic variants and epidemiological variables. At microscopy examination, G. duodenalis was the most prevalent parasite found (29.3%, 91/311; 95% CI: 24.3–34.7), followed by Entamoeba spp. (18.7%, 58/311; 14.5–23.4), Ascaris lumbricoides (1.3%, 4/311; 0.4–3.3), and Taenia sp. (0.3%, 1/311; 0.01–1.8). qPCR confirmed the presence of G. duodenalis in 76.9% (70/91) of the microscopy-positive samples. Of them, 65.9% (60/91) were successfully genotyped. Assemblage B (68.3%, 41/60) was more prevalent than assemblage A (28.3%, 17/60). Mixed A + B infections were identified in two samples (3.3%, 2/60). These facts, together with the absence of animal-adapted assemblages, suggest that human transmission of giardiasis was primarily anthroponotic. Efforts to control G. duodenalis (and other fecal-orally transmitted pathogens) should focus on providing safe drinking water and improving sanitation and personal hygiene practices.

Food Safety in Sub-Sahara Africa, An insight into Ghana and Nigeria

Food safety is a global concern in today's world, and harnessing food safety in Sub-Saharan Africa, especially Nigeria and Ghana are momentous. This review presents an insight into the situation of food safety in Nigeria and Ghana. Using a desktop review technique, research papers were evaluated to find major sources of food safety concerns. It was revealed that many studies reported on food contamination at the consumption level whereas few reported on the healthiness of the production chain. Improper handling of food at the local markets, vending sites hygiene practices of food vendors, and bad transportation and packing systems have all been implicated. Inadequate education is a major cause of food contamination, especially at the consumption level. Again, etiologic agents responsible for food-borne illness in Ghana and Nigeria range from viruses, fungi, parasites, and protozoans to bacteria. They include rotavirus, hepatitis A virus, Lassa fever (LHF), human noroviruses (HNoV), Aspergillus parasiticus, Aspergillus flavus, Aspergillus niger, Taenia solium, Ascaris spp., Toxoplasma gondii, Cryptosporidium spp. Enterobacter spp., Pseudomonas spp., Campylobacter spp., Escherichia coli. Staphylococcus spp., Salmonella spp., Vibrio cholerae and Listeria monocytogenes. Their toxins are responsible for numerous food contaminants. Some foods are contaminated with chemicals including pesticide residues, lead, mercury, etc. Laws of food safety are not well enforced leading to complications in the food production chain. Rigorous monitoring and evaluation coupled with surveillance and education to harness the situation and detect issues that compromise the right process is a necessity. Finally, intentional enforcement of regulations by regulatory agencies will go a long way to curb food contamination and food-borne illnesses within the region.

Cryptosporidium and Giardia infections in humans in Tigray, Northern Ethiopia: an unexpectedly low occurrence of anthropozoonotic transmission

Enteric protozoans Cryptosporidium spp. and Giardia duodenalis are among the leading causes of diarrhoea in children. These parasites have particular impact in low- and middle-income countries. In these countries, people often live in close contact with their animals, highlighting the potential role of zoonotic routes of transmission in disease spread. The occurrence and species/genotypes of Cryptosporidium and Giardia duodenalis infecting humans in Tigray, Ethiopia were investigated, along with the risk associated with infection. Stool samples from 249 asymptomatic people (4-80 years of age) in four rural districts in Tigray and 58 from symptomatic young children (1-33 months) attending health centres in Mekelle, Tigray's main city, were analysed for Cryptosporidium oocysts and Giardia cysts. Participants in the rural areas completed questionnaires regarding potential risk factors, with emphasis on livestock contact and sources of water. The occurrence of Cryptosporidium infection was 6% and 5% in people in the rural districts and young children from Mekelle, respectively; equivalent figures for Giardia infection were 29% and 14%. Molecular characterization of Cryptosporidium isolates revealed C. ubiquitum, subtype XIIa in a sample from rural districts, and C. hominis subtype IdA17 (1 sample) and IbA9G3 (2 samples) in infants from Mekelle with diarrhoea. For Giardia, Assemblage B predominated (22/25; 88%), but we also identified three samples with Assemblage A (AII). Our major finding was that, despite the close contact between people and livestock in our rural study sites, transmission of Cryptosporidium and Giardia between humans and their animals seems to be surprisingly uncommon. Our results are discussed in relation to other relevant studies, and also draws attention to the possibility that introduction of zoonotic species and/or subtypes, such as C. parvum, could have serious consequences for both human and animal health. As our study was conducted in Tigray, further investigation in different settings in Ethiopia could provide relevant information on transmission and zoonotic potential, and the potential for spread of zoonotic transmission. In addition, given the importance of these two parasites in causing diarrhoea in children, this information is vital for developing effective appropriate interventions against transmission that can be applied not only in Tigray or Ethiopia, but throughout Africa and beyond.

A novel genotyping method for Cryptosporidium hominis

Cryptosporidiosis remains the leading protozoan induced cause of diarrhoea-associated mortality worldwide. Cryptosporidium hominis, the anthroponotically transmitted species within the Cryptosporidium genus, contributes significantly to the global burden of infection, accounting for the majority of clinical cases in many countries. This study applied high resolution melting analysis, a post-real-time PCR application, to the differentiation of six globally prevalent C. hominisgp60-subtypes. This novel method targeted three microsatellite, tandem repeat containing genetic markers, gp60, the genetic marker upon which current Cryptosporidium subtype nomenclature is based, MSB, and MSE, by which to differentiate between C. hominis isolates. This multi-locus approach successfully differentiated between all six C. hominisgp60-subtypes studied, some of which, such as IbA10G2, are known to exhibit global ubiquity. Thus, this method has the potential to be universally employed as a sensitive, cost effective and highly reproducible means to rapidly differentiate between C. hominisgp60-subtypes. Such a method would be of particular utility in epidemiological studies and outbreak scenarios, providing cost effective, clinically accessible alternative to DNA sequencing. The success of this preliminary study also supports further analysis of an expanded C. hominisgp60-subtype range and the potential expansion of the multi-locus panel in order to improve the discriminatory power of this approach.

Physician Perception and Diagnosis of Intestinal Parasitic Infections among Patients with Gastrointestinal Symptoms in Ghana

This study evaluated physicians' perception and diagnosis of intestinal parasitic infections (IPI) in patients with gastrointestinal (GI) symptoms. This cross-sectional survey used a Google form questionnaire distributed online. Demographic and clinical practice information was solicited, including if “IPI was considered as a diagnosis in the last patient seen,” “if stool investigation was requested among the last patients seen,” and physicians' perception of the burden of IPI in the country. Using Pearson chi-square and multivariate logistic regression analysis, we tested the significance of the associations of the job cadre of the physicians and their perception of the IPI burden with consideration of IPI as a diagnosis in the last patient seen, request for stool investigation in the last patient seen, and overall frequency of the request for stool investigation. Ultimately, 184 physicians responded. The majority agreed to “often seeing patients with GI symptoms” (156, 84.7%), “not considering IPI among the last patient seen” (106, 57.6%), and “not requesting stool investigation among the last patient seen with symptoms” (136, 73.9%). House officers (81, 44.2%) constituted the highest proportion of physicians who considered IPI as a diagnosis among the last patient seen (39, 48.1%, p = 0.05). Most physicians (138, 75%) considered IPI as a burden in Ghana. They constituted significant proportions of the physicians who considered IPI as a diagnosis among their last patients seen (65, 83.3%, p = 0.02) and were twice more likely to consider IPI as a diagnosis among the last patients seen than their colleagues who did not consider IPI as a burden in Ghana (AOR 2.26, p = 0.04). The consideration of IPI as a diagnosis among patients with GI symptoms and request for stool investigations was low among physicians in this study. Further engagements with physicians in Ghana are needed to help improve their diagnosis of IPI in patients with GI symptoms.

Molecular Epidemiology of Human Cryptosporidiosis in Low- and Middle-Income Countries

Cryptosporidiosis is one of the most important causes of moderate to severe diarrhea and diarrhea-related mortality in children under 2 years of age in low- and middle-income countries. In recent decades, genotyping and subtyping tools have been used in epidemiological studies of human cryptosporidiosis. Results of these studies suggest that higher genetic diversity of Cryptosporidium spp. is present in humans in these countries at both species and subtype levels and that anthroponotic transmission plays a major role in human cryptosporidiosis. Cryptosporidium hominis is the most common Cryptosporidium species in humans in almost all the low- and middle-income countries examined, with five subtype families (namely, Ia, Ib, Id, Ie, and If) being commonly found in most regions. In addition, most Cryptosporidium parvum infections in these areas are caused by the anthroponotic IIc subtype family rather than the zoonotic IIa subtype family. There is geographic segregation in Cryptosporidium hominis subtypes, as revealed by multilocus subtyping. Concurrent and sequential infections with different Cryptosporidium species and subtypes are common, as immunity against reinfection and cross protection against different Cryptosporidium species are partial. Differences in clinical presentations have been observed among Cryptosporidium species and C. hominis subtypes. These observations suggest that WASH (water, sanitation, and hygiene)-based interventions should be implemented to prevent and control human cryptosporidiosis in low- and middle-income countries.

Increased diversity and novel subtypes among clinical Cryptosporidium parvum and Cryptosporidium hominis isolates in Southern Ireland

Reported incidence rates of cryptosporidiosis in Ireland are consistently among the highest in Europe. Despite the national prevalence of this enteric parasite and the compulsory nature of incidence surveillance and reporting, in-depth analyses seeking to genotype clinical isolates of Cryptosporidium on an intra-species level are rarely undertaken in Ireland. This molecular epidemiology study of 163 clinical Cryptosporidium isolates was conducted in Southern Ireland, from 2015 to 2018, in order to ascertain population subtype heterogeneity. Analysis was conducted via real-time PCR amplification and gp60 gene sequencing, which successfully determined the subtype designation of 149 of the 163 (91.4%) tested isolates. Overall, 12 C. parvum and five C. hominis subtypes were identified, with the incidence of the regionally predominant C. parvum species found to primarily occur during springtime months, while C. hominis incidence was largely confined to late summer and autumnal months. Additionally, one C. parvum and four C. hominis subtypes were newly reported by this study, having not been previously identified in clinical or livestock infection in Ireland. Overall, these data give insight into the diversification of the Cryptosporidium population and emergent subtypes, while also allowing comparisons to be made with clinical epidemiological profiles reported previously in Ireland and elsewhere.

Opinions and knowledge on globally important foodborne parasites among healthcare professionals at a tertiary teaching hospital in Nigeria

Foodborne diseases are important everywhere in the world, but the level of attention they receive varies by region. We surveyed the current opinions and knowledge regarding the globally most important foodborne parasites (FBP) among healthcare professionals in Abakaliki, Ebonyi State, Nigeria, by conducting a questionnaire survey among healthcare professionals in a tertiary hospital. We focused on the FBP ranked as the top five globally: Taenia solium, Echinococcus granulosus, Echinococcus multilocularis, Toxoplasma gondii, and Cryptosporidium spp., and gathered local expert opinions regarding their importance in Nigeria. Moreover, we surveyed the extent of healthcare community knowledge on transmission, manifestations and pathologies, and prevention of infections with these five FBP. Among the 205 healthcare professionals completing the survey, T. solium was selected as important in Nigeria by 143 (70%), E. granulosus by 91 (44%), E. multilocularis by 62 (30%), T. gondii by 132 (64%), and Cryptosporidium spp. by 123 (60%). Only 44 (21%) of the participants selected at least 15 of the 25 answers to knowledge questions that we considered as correct to select. The proportion selecting at least 15 of the correct answers was not statistically significantly associated with gender nor with experience level. Our results suggest that further education about FBP should target healthcare professionals at all levels.

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Knowledge on global top-5 foodborne parasites was evaluated at a Nigerian hospital.

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21% of the respondents selected ≥15 of 25 correct answers to knowledge questions.

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Further education on foodborne parasites for healthcare professionals is needed.

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70% of the respondents considered Taenia solium to be important in Nigeria.

Apparent overuse of antibiotics in the management of watery diarrhoea in children in Abakaliki, Nigeria

BACKGROUND

Diarrhoea remains an important cause of childhood mortality in Nigeria, with Rotavirus and Cryptosporidium reported to have the highest contribution. However, high use of antibiotics for treatment of paediatric diarrhoea has been observed, although World Health Organization guidelines discourage the use of antibiotics for treating acute diarrhoea. Here we investigated more closely management and treatment practices for acute paediatric diarrhoea, both in home and healthcare settings.

METHODS

Children under 5 years of age (n = 199) presenting at healthcare centres in Abakaliki, Nigeria with acute watery diarrhoea were included in the study. Background information on the children was collected by questionnaire, including home treatments, and clinical information including symptoms and treatment were provided by the healthcare centres. Analysis of faecal samples from the children indicated that over 90% had Rotavirus infection and over 6% Cryptosporidium infection. Data were compiled in a spreadsheet and analysed for associations between variables and use of antibiotics using logistic regression analysis.

RESULTS

Although most children were treated supportively (oral rehydration solution and intravenous fluids at home and in healthcare settings, respectively) over 15% were given anti-diarrhoea drugs at home and over 85% were also prescribed antibiotics at the healthcare centre, mostly ciproflaxin, but also metronidazole and gentamycin. The only variable positively associated with antibiotic prescription was diarrhoea more than three times per 24 h at admission.

CONCLUSIONS

It is clear that young children presenting with acute watery diarrhoea to healthcare centres in Abakaliki are likely to be prescribed antibiotics, despite there being no obvious reason that this treatment is appropriate. Our study results support the need for institution-based antimicrobial stewardship being implemented in Nigeria.